1. Field of the Invention
This invention relates to bedding products (including but not limited to mattresses) and in particular to bedding products having multiple firmness zones.
2. Description of the Related Art
Traditional bedding or seating products have either an inner spring core comprising a plurality of identically configured coil springs arranged in linear columns and rows or an inner spring core comprising a plurality of pocketed coils, also arranged into columns and rows. When such a spring core is used, it is typically covered with a pad or other covering material that surrounds and envelops the spring core. Sometimes, in the case of a bedding product, an additional padding layer known as a “topper” is attached to the top sleeping surface. A topper may also be attached to the bottom sleeping surface as well, so that the mattress can be flipped.
Traditional bedding or seating products typically have one degree of firmness throughout because all of the springs of the spring core are identical.
Alternatively, bedding and seating systems may have a resilient foam core. This foam core may be surrounded by perimeter bolsters, located around the edges of the sleeping or seating surface, i.e., at the head, foot, or sides of a mattress as those terms are known in the art. Foam core mattresses may also include toppers, in addition to a cover.
Also known in the art are bedding or seating products that have increased firmness in certain regions of the sleeping surface, such as about their perimeter edge portions or in the lumbar region. In particular, lumbar support schemes have included coils or foam elements within the core of different stiffness/resiliency from those employed in other regions of the mattress.
Present core systems add to the complexity of mattress assembly by requiring determination of desired firmness prior to core manufacturing. Also, once a core is assembled with a particular lumbar stiffness, it cannot be readily changed.
What is needed is an easily installed, versatile support member that can be placed in a desired sleep surface region late in the manufacturing cycle, so as to simplify the process and reduce costs.